In the field of dialysis, for example, sensors are mainly used for monitoring the most varied measuring parameters, and for instance the cleaning level of the blood is determined with the aid of absorbance measurements in the used dialysis liquid (DF), which is a chemical image of the cleaned blood. The absorbance measurements are performed here by means of and/or using an optical UV transmission sensor. In known assemblies, the sensor is a fixed component of the dialysis machine, so that each dialysis machine at which a desired variable or a corresponding measured value is to be output has to be equipped with one or several of such sensor(s), which requires intensive developments and is cost-intensive.
A dialysis center can use several of such dialysis machines at the same time or in a timely staggered manner. In doing so, the rejection of used dialysis liquid is discharged over a common line. Nevertheless, the corresponding sensors have to be plurally provided in the several dialysis machines.